Fixed missing operation counts in performance tests

Fixed missing operation counts in performance tests, which were dropped because their count was under the performanceUpdateFrequency. They are now logged at least at the end of the test. The magic line of code is:
```java
operations.addAndGet(iteration % performanceUpdateFrequency);
```

Updated ExampleTests with OperationSelector and fixed performance measurement.

Removed some warnings in test classes.
Hmm, you may be right about this. But then all tests like this are wrong and are already logging one iteration too late.